Why it works: Butter and milk are a kitchen classic. They rank in the top 7% of all ingredient pairs, and cooks put them together in 81,283 recipes. Both carry (z)-4-heptenal, which smells biscuit, cream. The science ↓
White Sauce
Ingredients
Directions
Make the sauce
In a bowl, knead the butter with the flour until well combined.
Melt the mixture in a saucepan over low heat, then gradually add the milk.
In a separate bowl, beat the egg yolk with the milk or cream.
Stir the egg mixture into the saucepan and cook over low heat, stirring constantly until thickened.
Finish
Add chopped parsley if desired.
Transcribed from a scanned cookbook and modernised for today's kitchens. Where the book gave no heat or time, or said "a moderate oven", the temperatures and times here may be modern equivalents rather than the book's own figures.
Explore the science
The flavor team
The pairs that carry this dish. Each one is judged two ways: how much their aromas overlap, and how often cooks already put them together.
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Butter + milktop 7% of all pairsSmell alikemoderateCooked together81,283 recipes
Shared aroma: (z)-4-heptenal (biscuit, cream).
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Butter + flourtop 12% of all pairsSmell alikelowCooked together124,287 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Flour + parsleytop 12% of all pairsSmell alikemoderateCooked together16,675 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Flour + milktop 14% of all pairsSmell alikelowCooked together78,219 recipes
Shared aroma: isobutyraldehyde (malty, green).
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Butter + parsleytop 15% of all pairsSmell alikemoderateCooked together28,563 recipes
Shared aroma: trans-2-hexenal (green, leafy).
Butter and flour barely smell alike, yet cooks put them together in 124,287 recipes: they work on texture and structure more than aroma.
Ranks compare each pair with 20,000 random ingredient pairs on CompKitchen. How we score pairs
What each ingredient does
- Butter
- Adds fat and richness, and helps form the base roux with the flour.
- All-purpose flour
- Thickens the sauce as it cooks with the butter and milk.
- Milk
- Forms the liquid body of the sauce that the flour thickens.
- Egg yolk
- Enriches the sauce and adds body when it is gently heated into it.
The step that matters
Stir the egg mixture into the saucepan. Egg yolk can curdle or scramble if it gets too hot too fast. Cooking over low heat while stirring constantly keeps the proteins smooth and lets the sauce thicken evenly.
Swap the parsley
The recipe marks parsley as optional. How well each one fits the dish's main ingredients (butter, flour, milk, egg):
- Nutmegfits better
- Cinnamonfits better
- Capersfits about as well
- Parsleythe original
Fit is the average pairing score against butter, flour, milk, egg. Candidates are from the same food group and used in at least 100 recipes.
“What each ingredient does” and “The step that matters” were written by Claude from this recipe’s own method and reviewed in samples by CompKitchen.
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